1. Field of the Invention
The present invention relates to an image forming apparatus and a process unit identification method used in multifunction peripherals and facsimile apparatus.
2. Description of the Related Art
Process units such as toner cartridges and drum units can be inserted into or removed from an image forming apparatus, and are replaced when the life of the process unit expires.
In recent years, non-genuine (hereinafter called xe2x80x9cpiratedxe2x80x9d) process units have gone into circulation, and there has been a problem that image quality cannot be guaranteed if a pirated process unit is used in an image forming apparatus. A technique, allowing a print operation of the image forming apparatus for the genuine process units uses a specific code data read from a memory unit of the process unit. When specific code data is stored in the memory unit, and the process unit is inserted into the apparatus, this solves the above problem.
However, this technique cannot be applied to the pirated process units made by recycling used genuine process units.
The present invention is provided in view of the above problem, and it is an advantage of the present invention to provide the image forming apparatus where pirated process units made from recycled used genuine process units cannot be used.
To solve the above problem, an image forming apparatus of the present invention includes a first memory where an ID (Identification) code and a count value are written, a process unit that can be inserted in and removed from the image forming apparatus, a memory access unit which can access the first memory to read out the ID code and read out and write the count value, and a second memory where the image forming apparatus stores the ID code and the count value, and further includes a control unit which limits an image forming operation of the image forming apparatus if the ID code of the first memory matches the ID code of the second memory and the count value of the first memory has a predetermined relation to the count value of the second memory.
As the count value stored in the second memory of the image forming apparatus changes every time the process unit is exchanged, the count value set in the first memory of the used process unit does not match the count value stored in the second memory of the image forming apparatus if the process unit including the count value used before is fixed in the apparatus, and the image forming apparatus can recognize that the fixed process unit is the recycled pirated one.
In the configuration, an image forming operation is not carried out when the control unit determines that the process unit is pirated, as the control unit limits the image forming operation of the image forming apparatus if the ID code of the first memory does not match the ID code of the second memory, so that problems such as deteriorating image quality, etc. can be surely prevented.
Moreover, an embodiment for changing the count value stored in the second memory of the image forming apparatus every time the process unit is exchanged is provided. The control unit changes the count value stored in the second memory and writes it in the first memory, when the ID code of the first memory matches the ID code of the second memory and the memory access unit does not read out the count value. This occurs on the condition that the count value is not written in the first memory in an initial state.